Re: [PHP] truncate a mb-string to a given octet length?

eddie,

you were quite right and i was wrong.

after discovering that the longest utf8 varchar column that mysql will allow
is varchar(333), i did some tests. on a varchar(255) column, mysql allows
strings with up to 255 utf8 characters to be inserted. and it truncates at
255 characters observing utf8 character sequences.

now i have to go back to the script that convinced me otherwise and figure
out what i misunderstood in it.

section 10.4.1 of the manual could be explicit about it. when i read it i
got the clear impression the parameter referred to octets.


On 6/12/09 1:22 PM, "Tom Worster" <[email protected]> wrote:

> On 6/12/09 11:52 AM, "Eddie Drapkin" <[email protected]> wrote:
> 
>> Correct me if I'm wrong, but should varchar 255 with a utf8 character set
>> mean 
>> 255 unicode characters, not octets?
> 
> in mysql, the length refers to the storage space of the string, not the
> decoded character count. i don't know about other dbms.
> 
> 
>> On Fri, Jun 12, 2009 at 11:50 AM, Tom Worster <[email protected]> wrote:
>> say a table in the db has a varchar(255) column, 255 being the max number of
>>> octets of strings that can go in the column. now say the php script very
>>> occasionally has to deal with utf8 input strings with octet length > 255 --
>>> it needs to select rows matching the input string or insert the input
>>> string.
>>> 
>>> so what i think i need is a function to truncate a utf8 string to the
>>> longest valid utf8 string that has octet length <= 255.
>>> 
>>> is this what mb_strcut() is for? i'm having a hard time understanding the
>>> man page for that function.